Re: Lost toy at sitter's house, advice?
If a toy comes in my house, it becomes everybody's toy for the day. The kid who brought it takes it home, but it's not going to be clutched in his or her hands all day. ALL toys are for sharing. So, if they bring it, I ask "Are you willing to let other kids play with that?" If they say "no", then the toy goes back out to the car to sit in his or her carseat and wait for them.
Eventually, the parent gets tired of me putting the drama back on them and the child, they just stop bringing toys over at all.